Learn Hardcore Croatian: U proljeće često pada kiša, ali zrak je svjež i ulica je puna cvijeća. - In spring it often rains, but the air is fresh and the street is full of flowers.

Location (where?) → u
- locative
  - u gradu = in the city
Direction (where to?) → u
- accusative
  - ići u grad = to go to the city
Time (when?) → very often u
- accusative, especially with parts of the day and seasons
  - ujutro, u podne, u jesen, u proljeće

So u proljeće literally feels like “into spring” but is understood as “in spring / in the spring”. Using the accusative for time expressions like this is standard and very common.

Can I also say u proljeću, and is there a difference from u proljeće?

U proljeće is the normal, everyday way to say in (the) spring.

U proljeću (locative) technically exists, but:

It sounds unusual or poetic in modern usage.
In everyday speech and writing, almost everyone says u proljeće.

So for normal conversation and writing, you should stick to u proljeće.

Could I say na proljeće instead of u proljeće? Is there a difference?

Both exist, but they are not fully identical:

u proljeće
- Neutral, most common.
- “In spring (as a season, generally).”
- Can describe typical weather or habits.
- Example: U proljeće često pada kiša.
na proljeće
- Often implies “when spring comes / in the coming spring”, a bit more like “this/next spring” in English.
- Slight nuance of a particular spring as a time point in the (near) future:
- Example: Na proljeće ćemo putovati. = We’ll travel (when spring comes / this spring).

In your sentence, which states a general fact about the season, u proljeće is the more natural choice.

Where can I put često in the sentence? Is U proljeće često pada kiša the only correct word order?

Croatian word order is flexible, so često (often) can move, but the nuance changes slightly. Some common options:

U proljeće često pada kiša.
- Neutral: “In spring it often rains.”
Često u proljeće pada kiša.
- Emphasizes “often”: “It is often the case that in spring it rains.”
U proljeće pada često kiša.
- Possible, but sounds less natural; marked word order.

As a learner, it’s safest and most natural to keep često close to the verb:
U proljeće često pada kiša. or Često pada kiša u proljeće.

Why do we say pada kiša and not something like “it rains” with an “it” subject?

Croatian usually doesn’t use a dummy subject like English it. Instead, you just have:

pada = “falls”
kiša = “rain”

So pada kiša literally is “rain is falling,” which corresponds to English “it is raining.”
You can also reverse the order:

Kiša pada. – also correct, just different emphasis.

There is also a verb for “to rain”: kišiti:

Kiši. = It’s raining.

So Croatian can either:

use pada + kiša (rain is falling)
or the verb kišiti (to rain)

without any dummy it.

Is there any difference between pada kiša and kiša pada?

Both are grammatically correct. The difference is mostly emphasis:

Pada kiša.
- Slight emphasis on the action (“It’s raining (rain is falling)”).
Kiša pada.
- Slight emphasis on rain as the subject (“The rain is falling”).

In longer sentences like yours, U proljeće često pada kiša sounds more natural and fluent than … često kiša pada, though the second is not wrong.

What does ali mean, and do I always need a comma before it like in …, ali zrak je svjež…?

Ali means but and introduces a contrast:

Pada kiša, ali zrak je svjež.
= It rains, but the air is fresh.

In standard Croatian orthography, you do normally put a comma before ali when it joins two clauses (two “mini-sentences”):

Došao je, ali je otišao brzo.

So the comma in U proljeće često pada kiša, ali zrak je svjež… is correct and expected.

Why is it zrak je svjež and not svježa or something else?

Adjectives in Croatian must agree with the noun in gender, number, and case.

zrak = air
- masculine, singular, nominative

So the adjective must also be:

masculine
singular
nominative

The base (short) form is:

svjež (masc. sg. nom.)
svježa (fem. sg. nom.)
svježe (neut. sg. nom.)

Because zrak is masculine, we say:

zrak je svjež = the air is fresh

If the noun were feminine, e.g. voda (water), it would be:

voda je svježa = the water is fresh.

Why is it ulica je puna cvijeća and not pun cvijeća or puna cvijeće?

Two things are happening here: adjective agreement and case after pun/puna.

Adjective agreement
- ulica = street
  - feminine, singular, nominative
- The adjective pun (full) must match this:
  - puna = feminine, singular, nominative
So: ulica je puna …
Case after “full of”
In Croatian, pun/puna/puno is followed by the genitive case to express “full of something”:
- puna ljudi = full of people
- puna problema = full of problems
- puna cvijeća = full of flowers
Cvijeće (flowers) in the genitive singular is cvijeća, so:
- ulica je puna cvijeća = the street is full of flowers.

Puna cvijeće is wrong because cvijeće is not in the correct case (it would need to be genitive).

What kind of noun is cvijeće/cvijeća? Why does it mean “flowers” but look singular?

Cvijeće is a collective neuter noun. That means:

It is grammatically singular (neuter).
But its meaning is plural/collective: “flowers, blossom, floral growth.”

Its forms:

Nominative singular: cvijeće (used for “flowers”)
Genitive singular: cvijeća

Because puna requires the genitive, you get:

puna cvijeća = full of flowers

If you want to refer more clearly to individual flowers, you can also use the normal plural of cvijet (flower):

ulica je puna cvjetova = the street is full of (individual) flowers

Both puna cvijeća and puna cvjetova are correct; cvijeće/cvijeća is just more collective/massy.

Can I drop the second je and say …, ali zrak je svjež i ulica puna cvijeća?

Yes, you can. Both are possible:

… ali zrak je svjež i ulica je puna cvijeća.
… ali zrak je svjež i ulica puna cvijeća.

In the second version, je is simply understood with the second part (ulica [je] puna cvijeća). This is quite natural in Croatian when two clauses share the same verb biti (to be).

Your original sentence with both je’s is perfectly correct and maybe a bit clearer for learners.

Why are there no words for “the” in zrak je svjež and ulica je puna cvijeća? How do I know if it means “the air / the street”?

Croatian has no articles (no “a/an” or “the”). Whether you translate zrak as air or the air depends on context, not on a specific word in Croatian.

In this sentence:

zrak je svjež
→ given the context (“in spring”), English naturally uses the air is fresh.
ulica je puna cvijeća
→ in context, you’d usually say the street is full of flowers.

Croatian just says zrak and ulica; the listener uses context to decide whether it’s meant in a general sense or a specific one.

Is the overall word order fixed, or could I rearrange parts like zrak je svjež i ulica je puna cvijeća?

The basic word order is Subject – Verb – Rest, but Croatian is flexible. Some alternatives:

Zrak je svjež i ulica je puna cvijeća. – neutral.
Svjež je zrak i ulica je puna cvijeća. – emphasizes “fresh is the air.”
Zrak je svjež, a ulica je puna cvijeća. – a instead of ali, slightly weaker contrast.

All are grammatically correct. The original version is the most neutral and natural for a learner, so it’s a good model to follow.